<template>
  <Select 
    style="width: 100%" 
    @dropdown-visible-change="handleFetch" 
    v-bind="$attrs" @change="handleChange" 
    :options="getOptions" v-model:value="state"
    ref="selectRef"
  >
    <template #[item]="data" v-for="item in Object.keys($slots)">
      <slot :name="item" v-bind="data || {}"></slot>
    </template>
    <template #suffixIcon v-if="loading">
      <LoadingOutlined spin />
    </template>
    
    <template v-if="showAddBtn" #dropdownRender="{ menuNode: menu }">
      <v-nodes :vnodes="menu" :loading="loading" />
      <a-divider style="margin: 4px 0" />
      <a-button type="text" style="padding: 4px 8px; cursor: pointer; width: 100%" @click="handleAdd">
        <PlusOutlined />
        新增
      </a-button>
    </template>

    <template #notFoundContent v-if="loading">
      <span>
        <LoadingOutlined spin class="mr-1" />
        {{ t("component.form.apiSelectNotFound") }}
      </span>
    </template>
  </Select>
</template>
<script lang="ts">
  import { defineComponent, PropType, ref, watchEffect, computed, unref, watch, h } from "vue"
  import { Select } from "ant-design-vue"
  import { isFunction } from "/@/utils/is"
  import { useRuleFormItem } from "/@/hooks/component/useFormItem"
  import { useAttrs } from "/@/hooks/core/useAttrs"
  import { get, omit } from "lodash-es"
  import { LoadingOutlined, PlusOutlined } from "@ant-design/icons-vue"
  import { useI18n } from "/@/hooks/web/useI18n"
  import { propTypes } from "/@/utils/propTypes"

  type OptionsItem = { label: string; value: string; disabled?: boolean }

  export default defineComponent({
    name: "ApiSelect",
    components: {
      Select,
      LoadingOutlined, PlusOutlined,
      VNodes: defineComponent({
        props: {
          vnodes: {
            type: Object,
            required: true,
          },
          loading: {
            type: Boolean,
            required: true,
          },
        },
        render() {
          return this.loading ? h(LoadingOutlined) : this.vnodes;
        },
      })
    },
    inheritAttrs: false,
    props: {
      value: [Array, Object, String, Number],
      numberToString: propTypes.bool,
      api: {
        type: Function as PropType<(arg?: Recordable) => Promise<OptionsItem[]>>,
        default: null,
      },
      // api params
      params: {
        type: Object as PropType<Recordable>,
        default: () => ({}),
      },
      // support xxx.xxx.xx
      resultField: propTypes.string.def(""),
      labelField: propTypes.string.def("label"),
      valueField: propTypes.string.def("value"),
      immediate: propTypes.bool.def(true),
      alwaysLoad: propTypes.bool.def(false),
      showAddBtn: propTypes.bool.def(true),
      options: propTypes.array.def([]),
    },
    emits: ["options-change", "change", "update:value", 'add-item'],
    setup(props, { emit, expose }) {
      const options = ref<OptionsItem[]>([])
      const loading = ref(false)
      const isFirstLoad = ref(true)
      const preParam = ref()
      const emitData = ref<any[]>([])
      const attrs = useAttrs() as any
      const { t } = useI18n()
      const selectRef = ref()

      // Embedded in the form, just use the hook binding to perform form verification
      const [state, setState] = useRuleFormItem(props, "value", "change", emitData)

      const getOptions = computed(() => {
        const { labelField, valueField, numberToString } = props
        const tempOptions = unref(options).length > 0 ? unref(options) : props.options
        let data = tempOptions?.reduce((prev, next: any) => {
          if (next) {
            const value = get(next, valueField)
            prev.push({
              ...omit(next, [labelField, valueField]),
              label: get(next, labelField),
              value: numberToString ? `${value}` : value,
            })
          }
          return prev
        }, [] as OptionsItem[])
        return data.length > 0 ? data : props.options
      })

      watchEffect(() => {
        props.immediate && !props.alwaysLoad && fetch()
      })

      watch(
        () => state.value,
        (v) => {
          emit("update:value", v)
        }
      )

      watch(
        () => props.params,
        () => {
          !unref(isFirstLoad) && fetch()
        },
        { deep: true }
      )

      async function fetch() {
        const api = props.api
        if (!api || !isFunction(api)) return
        options.value = []
        try {
          loading.value = true
          const res = await api(props.params)
          if (Array.isArray(res)) {
            options.value = res
            emitChange()
            return
          }
          if (props.resultField) {
            options.value = get(res, props.resultField) || []
          }
          emitChange()
        } catch (error) {
          console.warn(error)
        } finally {
          loading.value = false
          //判断选择模式，multiple多选情况下的value值空的情况下需要设置为数组
          unref(attrs).mode === "multiple" && !Array.isArray(unref(state)) && setState([])
        }
      }

      async function handleFetch(visible = true, immediate = false) {
        if (visible) {
          if (props.alwaysLoad) {
            await fetch()
          } else if (!props.immediate && unref(isFirstLoad)) {
            await fetch()
            isFirstLoad.value = false
          }
        } else if (immediate) {
          await fetch()
        }
      }

      const handleAdd = () => {
        emit('add-item')
        selectRef.value.blur()
      }

      function emitChange() {
        emit("options-change", unref(getOptions))
      }

      function handleChange(_, ...args) {
        emitData.value = args
      }
      expose({ handleFetch })
      return { 
        selectRef,
        state, 
        attrs, 
        getOptions, loading, 
        t, handleFetch, 
        handleAdd,
        handleChange, fetch }
    },
  })
</script>
